请问如果表示时间 by ten o'clock中by的意思这个by指的是在十点以前,还是在十点那个时间点?

请问如果表示时间 by ten o'clock中by的意思这个by指的是在十点以前,还是在十点那个时间点? by ten o'clock 请问这里by和till为什么不能互换?我知道by是表示“在.之前”,而till是表示“到.为止”.我不懂的是,为什么下面2句,不能同时使用by和till?1.He’ll finish the work (by) ten o’clock this morning,他将在10点 You must let me have the annual report without ___ by ten o'cl ock tomorrow morning.You must let me have the annual report without ___ by ten o’cl ock tomorrow morning.A.failure B.hesitation C.trouble D.fail说明原因 by ten o'clock意思by ten o'clock翻译是……其中by翻译成什么 请问单质O,I,Br,Cl的氧化性顺序 I have to be in bed by ten o'clock.这句中 by ten o'clock是什么意思,为什么不是at,have to be in bed 是什么句型. 想问问by在各句子的用法,如果没有包括by的所有用法,希望帮我补充,1.I live by the river.2.I have to go back by ten o'clock.3.The thief entered the room by the window.4.The student went to park by bus. HClO4的结构式是什么是H-O-O-O-O-Cl还是 OII H-O-Cl =O,如果都不是,请给出正确的IIOOII H-O-Cl =O IIO不是应该共价键吗 She has to be in bed by ten o'clock jack has to go to bed by ten o'clock 改为一般疑问句 I have to be in bed by ten o'clock.[用in bed提问] She is to be here by ten o'clock.这里用be干什么? I have to be home by ten o'clock.为什么不是be at home? I have to be in bed by ten o’clock.的同意句是什么? have,to,in o'clock,I,bed,by,be,ten(.)连词成句 英语首字母填空 I have to b( ) in bed by ten o'clock. I'm supposed to be at home by ten o'clock at night.